The purpose of this study is 1) To determine whether the use of antibiotics and tocolytics in patients with preterm labor will improve perinatal outcome as compared to use of tocolytics alone; i.e., is subclinical intraamniotic infection a factor in preterm labor. 2) To assess a scoring system for occult intraamniotic infection. and 3) To assess whether interleukin-1 levels are predictive of subclinical infection and failed tocolysis.